The detection of highly explosive compounds, such as those used in land mines, is a necessity for modern warfare and counterterrorism. Sensing such explosives is a difficult task due to the low vapor pressure of common explosive materials, such as trinitrotoluene (TNT) and related nitroaromatic explosives, which typically have a vapor pressure in the parts per million (ppm) range or lower.
Many explosives detectors currently available, such as ion mobility spectrometers used in airports, are not portable. Sensors based on fluorescence quenching are field-deployable, but are relatively bulky and consume large amounts of power, thus making the devices hand-held portability questionable. Fluorescence-quenching sensors additionally have the detraction of photo-degradation issues of the organic sensing materials used.
With the current worldwide emphasis on counterterrorism and homeland security, an inexpensive, portable, and highly sensitive explosives detector is urgently needed to provide the necessary capabilities for eliminating the substantial threat to human life posed by such explosives.